Unknown. The answer to this question is that we do not know at this time.
Joint Hypermobility. Imo more women have fibromyalgia (fm) due to greater joint hypermobility syndrome (jhs) penetrance in female line. Jhs potentiates for ease of childbirth & infant survivability. The bristol criteria define jhs. Jhs potentiates for greater sij ligament injury & laxity secondary to multiple childbirths & mechanical trauma. Jhs, an inherited condition, also explains the fm familial phenomenon.